This invention relates to a fluid control device for use in a fluid-operated braking system, primarily for a motor vehicle, the control device being of the general kind in which first and second valves are operatively inter-related and respectively arranged to control fluid flow in a first flow path between fluid inlet and outlet ports and a second flow path through an exhaust port. The invention also embraces a braking system incorporating the aforesaid fluid control device.
Some conventional control devices of this general kind employ solenoids operated by pulsed control techniques in order to produce rapid valve switching. Such control devices tend to be relatively heavy and robust in order to withstand the necessary switching and can therefore be costly. They also have the disadvantage that they cannot readily provide proportional control of fluid output for brake application.